The sporadic emergence of these caddisflies diminishes the importance of the freshly emerged adults and pupae, but they have unique periods of vulnerability as larvae during the day and again as diving egg layers at dusk that can make them very important. A taxon can only have one common name attached in the title but this is one of those genera whose species come in a variety of colors and descriptive common names. In the West their bodies generally come in tan to brown shades with matching wings, their wings can be speckled grayish tan or even almost black as with an eastern species. Some western rivers have astounding populations. See Glossosomatidae for more information. Where & WhenRegions: East, Midwest, West
» Genus Glossosoma (Little Brown Short-horned Sedges)
13 species aren't included.
Time Of Year (?): Early Summer
Preferred Waters: Riffle sections
Time Of Day (?):The pupae emerge on the surface, or by rising to the surface and then swimming to shore. The generally tend to trickle off all day in numbers too few to attract much interest or notice from either angler or trout.Egg-Laying Behavior
variable and sporadic
Time Of Day: evenings, often at last lightFemales dive underwater to oviposit. They can swarm in tremendous numbers, often mixed with several species.Larva & Pupa Biology
Current Speed: Fast, for most speciesBecause Glossosoma cases are built to a fixed size, the larvae have to abandon them and build new ones as they grow. In the process they often accidentally or deliberately end up drifting downstream for awhile. They synchronize this activity as tightly as most species synchronize emergence, prompting trout to feed selectively on the larvae. Even better news for the angler is this activity is diurnal. Unfortunately, the timing is not predictable and while generally a morning occurrence, it can happen any time of day. A further handicap is that the behavioral drift (Behavioral drift: The nymphs and larvae of many aquatic insects sometimes release their grip on the bottom and drift downstream for a while with synchronized timing. This phenomenon increases their vulnerability to trout just like emergence, but it is invisible to the angler above the surface. In many species it occurs daily, most often just after dusk or just before dawn.) is not visible. The angler will only know it's happening by periodically seining the drift or fishing proper imitations until the fish start to respond.
Shelter Type: Rocks, shaped kind of like a turtle shell
This usually occurs several times during their development in the spring and summer. In Caddisflies, LaFontaine recommends imitating the naked pinkish-colored larvae drifting without their cases. They also come in shades of pale tan or yellow.
2 Underwater Pictures of Glossosoma Saddle-case Makers:
Date AddedOct 4, 2006
CameraPENTAX Optio WPi
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